these things are getting expensive, check out the other thread started by ronwhite. there are some 3rd party ones on ebay for about S$30+
if you're desperate for shooting fireworks these few days, get a cd audio cable, slice off one of the 4 connectors to fit your remote port, then use the wires to short for focus, and all three for shutter release. cheap simple dirty quick diy. don't worry, no current to electrocute you and you won't damage your camera either. miscue is equivalent to intermittently half-pressing and releasing shutter.
